lindquist



D. L. LINDQUIST SAFETY DEVICE FOR ELEVATORS Filed Aug. 27, 1923 3 Sheets-Sheet 1 CWT D 160 fizzfntoz M 4 3:, L; slum,

" FEB. 19, 1929. 1,702,515

D. L. LINDQUIST SAFETY DEVICE FOR ELEVATORS Filed Aug. 27, 1923 3 Sheets-Sheetf 2 awvemto'c v :Q Q.

Qbbom Feb. 19, 1929. 1,702,515

D. L. LINDQUIST I SAFETY DEVICE FOR ELEVATORS Filed Aug. 27, 1923 3 Sheets-Sheet 3 avwentoz 33%;; @bfome M C LLAW Patented Feb. 19, 1929.

UNTED TT DAVID L. LINDQUIST, OF HARTSDALE, NEW YORK. ASSIGNOR TO OTIS ELEVATOR COMPANY, OF JERSEY CITY, NEXV JERSEY, A CORPORATION OF NEW JERSEY.

SAFETY DEVICE FOR ELEVATORS.

Application filed August 27, 1923. Serial No. 659,442.

My invention relates to elevators or similar apparatus in which a car or load carrying means is operated within certain definite limits of travel and which in the topping operation is adapted to be retarded by an elect ic dynamic brake.

It is customary to i rrovide automatic slow down and stop iii the terminal landinps of elevators, or similar load can i operated within certain lliflulit li travel and an ole-sl de (lynantic. hrolee is Tu to auton'iatically retard th elem tor. 91 ous trouble would result it the dynamic braking action should tail to rozird he elevator in the stopping operation at tho tt'rminal stopping points. lVith high speed elevators in particular, it is practically impossible to provide sufficient distance o t overrun beyond the floor landings at the top and bottom of the hatchway or well room, so as to prevent the car striking the overhead worl; or the bottom of the pit ot the hatchway should the dynamic braking action upon the motor tail to retard the car sutliciently n the stopping operation, thereby permitting the car to continue to run at practically toll speed, until the final up or down limit stop switch is opened to cut oil the power to the motor.

The present invention has for its object to pro ide means to effect the mmediiite interruption ot' the power to the n'lotor and apply the clan ator mechanical brake to stop the car in case the dynamic brake does not sntlioiently retard the car during the normal aw tomatic slow down as it approaches its terminal stopping points.

I attain this object by the mtchanism illns trated in the accompanying drawings, in which Figure 1 shows the application o? my invention to an elevator d rivcn by a two speed alteruating current motor in the control of which the nit-ans to etfect the immediate interru tion of the power to the motor as mentizriiotl above is dependent upon the amount of current in the slow speed windings oi the motor.

Figure shows the application ot' my ir venlion to an elevator driven by a two speed alternating current motor in the control of which the means to oilect the immediate interruption ot the power to the motor as mentioned above is dependent upon the speed of the elevator and upon the opt-ration of the electromagnet switch controlling the fast and slow speeds of the motor.

Figure 3 shows the application of my invention to an elevator driven by a direct current motor in the control of which the means to effect the immediate interruption of the power to the motor as mentioned above is dependent upon the current in the armature of the motor, the voltage across the armature, or the current in the motor field; or upon the combined ettect of any two or all three of these.

Referring: to all the figures in detail, an elevator (a r C is shown in a hatchway A suspended from one end of a hoisting rope or eable 1 that is led from the car over an overhead work B and from there down to a driving sheave 2 on a shaft 3 of an electric motor D that is adapted to operate the car. There is the usual electro-mechanically operated brake H for stopping the ear; also the top and bottom landings E and F. For controlling the ear C to stop it at the terminal landings, there are switches 4. 5 and 6 near the top floor landing E adapted to be operated by the movement of the car in the order named to stop the car at the top floor landing and switches 7, 8 and 9, similar to switches 4, 5 and 6, near the bottom floor landing l adapted. to be operated by the movement of the car in the order named to stop the car at the bottom floor landing. To the side ot the car C there is atlixed a cam 10 for operation the switches 4i, 6, 7, 8 and 9 and in the car there is a controlling switch G for operating the car. There are also the usual electromagnetically operable up and down reversing switches I and J for controlling the motor D. and consequently the movement of the car, the switch I controlling the motor for the ascending direction of car travel and the switch J for the descending direction of travel.

in Figure. l in addition to the above parts there an olectroanagrncticall y operabl 51st speed switch K to control the speed oi the motor T l, which in this case is shown a; a threephase two speed alternating current motor. There 's an electro-inagm tieall operable switch L having two series coils or win. s 11 and 11', and two making contacts 12 and 12.

The ope "lition of the apparatus Figure l i s as follows. Assume that the ele ill) tor car C is at its bottom terminal hinil F and that it is desired to operate. it to ezin e to tzirel to its top terminal flootin tin: E. The lever 13 of the ear switrh G will be moved to the right tttlti its eontzletsegment 14 brought into Contact contact 15 ot' the switch, whereupon :1? electrical eireuit will be established as: lows from line I. by wire 16. Contact t? of the up reversing switeh l. by wire 18. common wire 19 of contacts 20 and 21 of the switeh (t. Contact 20. segment 14 and eontnet 15.1w wire 22, through a winding 2 of the up lQV(lswitch I. by wire 2 through contacts 23 o the up limit stop switijh 3. by wire tion point 2?. by wire through eontzn ot' the up limit stop switch 6. by wire itl. jun-*- tion point I} by w re 33 junetion point $323. by wire 34. contact 35 ot' the speeil switeh K. by wire 36 to the line it. The whirling 23 of the up revel-r ng witish i has hm n ener- -"izetl 21:5 1: result of the rlosinv' ot the 1 ireuit just trueetl unsl operntm E f. win; switch I to close its J()11t;at'ts.,tlt1ti the Suppl; circuits to the hoistnr to operate 11ml hoist the ear.

The ll1'3!l(( it will he releusetl at the same, tim (ireuits to the inoto are as follows: from line l. by wire 16, Contact 17 and eontua't 37 ot' the up reversing switeh I. now eiosetl. by wire 38. innrtion point 391; wire it). through the .Yi'iltiitlff it of the eleetro-imignetieatl operahie switch L. by wire 41. three. :1 slow eperil wind 42 ot the motor. ll) w 43. contact 4% of th fast speed switeh K. by wire 45, through contacts 46 of the hast speei wi eh K. by wire 45. through another slow speetl winding of the motor. by wire 4!). junction point 33. b; wire It eontaet 37 of the hast fip ctti switeh rire ii) to the line it. Another "ll" e l to the motor D at this time is its to llows from line Hi1 wire 50 ontzle 1 tl'tfi 52. now closed, ot'the up r vers r switeh I wires; .3 and junet on int through th \Yintlii '11 ot the elertro ni netieztlilv ope "iii" '11 L. lav wi e through another hm: speed winiiih 59 oh motor. h wi .35). th '-Z tl. 1'il('()llt;\ttr (it) of me fast speed i-7\\'2t ll K. b wire til. ("on 1.. to eont ir treeeil. segrl ire thron wire 6'4". through the winding: (it? of the speetl s 'HtCll K, by wire 69. eontst t 22;: at the zaii opening! its bottom contnets bet'ore :losmg its top wntaets. With the. top crn acts of the switch K eloseti. zinil thehottoin eontziets open. the motor is, operating on the test speeii windings the slow speed windings of the notor having been :-;lm1't-eireiiiteil. T euits to the fast speed windings of the D are as follows: tron'l line i by wire it}. eon-- tttCtS i7 anti 3? of the up reve 'swit h I. ii wire 38, jniietion point 23.). h tin't T1 of the that speed th eontziet oi this swi 'h fast ee l wiirhr s by wire -17. by w. ot' the fast --;pee t- -witr;i U 36 to the time it Another t'iln'tt t o the motor fast spe d winilin H l. hr wire so. to reY-eisin" switrh i. I, i s ill and 5}. tion poiit 5 7. by wire to. through eontztet: 7 21ml :8 now eiosetl ot' the tast sp ed switeh K. lax w re Ti). 1: ((Witlit' (30 ot the switeh. by wire throi i ifirt speetl wind ngs St) tin-l T3 iotor t 1. mail t the motor. 21ml by wire :ii' to the line it .is

bet-ore.

now 11ml The hoisting motor 1) speeil \fli'ltltlt ee l.

'Lze eiir opera-An [ti ininzii thor l r.

opening; of the re:

toe

eievzitor will b -r= luee l to pa i the elevator to he. at the hi T the musing the winding to her whirh w re (lose-i hen the wiiuli ersi'izetl :iml rlowe i hott n r ntzn Thi ".'E in the motor i) open open (he retw' l ne torque or the 1 l :ietion o. l

hm"? the slow r will It :35 terizi nzil lanioinir'. mm

7 7 'intl iiiiof 1:2; .11 an i 1 of the .;h the low speed wind *ill beeonie energized and The (.fiiifHiS of the nwit h Ti. being eonlIZU Lil

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nected in parallel by the. wires S2 and S with ergized so that contacts 12 remain closed. When the cam 10 strikes the limit: stop switi'h (l. cau ing it to open its contacts. and elfect the de-ener; ytution of the windinn 23% ot' the reversing switch I. thereby etlcctingth' oi aeninq of the contacts of the reversion switch and the application of the mechanical brake il the speed of the hoistin fniotor and inrscqucntly the speed of the cut will have been sutlicienllv reduced by the electric dynam c brak ction of the m to so that he application of the mechanical brake ll. when the car is at a point in its 3.1"! vol correspond ing: to the opening: of limit .sn itch (3. will 11h the car at the top terminal tloor lanai without any possibility of the car oasti into the overhead work If. however. dynamic brake action of the motor were re-- duced or entirely absent and if the mechanical brake be applied when the car is at a point in its travel corresponding to the opening of limit switch 6. the car would coast a much greater distance than when the dynamic brake action is pr sent and would not only not stop at the top terminal landinen but in all probability would coast far enough to strike the overhead work. To overcome this ditliculty, the mechanical brake isapplied sooner when the dynamic brake action is not sutlicient t: ru'operhi retard the car. This is accomplished by mean of the lim t stop switch 3 with contact in connection with contacts '2 on switch l). The lack of sul'licient curr wit to energize the windii 4 ll and ll of the witch l. or in o h r words the lack of sutlicient d nan'iic brake action. for the reason that one phase of the slow d windings of the hoisting motor is open, or for auv other reason. would result in the coin tat 1' 1:2 remain ng one?! an" ther f r the tlc ailtlgflltlth ll of the l't lllf,{' suit .1 \vintlin 2:: when the lim t l w tch 3 opens. contacts 1; would no i 7 contacts Q5 of th s limit witch. The auxiliary limit tch 3 zrran ed to be opened immediately afte' the oi iening of imitswitch 1- or as soon thereafter H's will permit of switch ll closing its contacts in normal operation. The openin; of the reversing: switch at this time permits the inechenical broke H to be applied whei the car at LL point in its travel correspor.ding to the opening of the limit switch 5, and the car is brought to rest entirely by mechani -al brake ejer sh uni ac ion. The distance available in which the air may slide before striking the over itfitl work is however, much greater in this case than when the b "ake applied when the ear is at a point corresponding to the opening of limit switch 6 and therefore there is little chance of the ar coastim; far enough to strike the overhead work. 7

ln Figure 2, in addition to the parts given above as common to all the figures, there is an electr rmagnetically ope fast speed switch K to control the speed of motor M, which in this case is shown as a three phase two speed alternating current motor as in Figure 1. There also an electro ma ineti cally operable switch M having a coil. 84' and breaking contact 85, adapted in case of the fa ilure of the electric dynamic brake zctarduion or slow down of the ear i in stopping at it t rniiiml landings including a failure of the fa t speed switch to open its iop contacts at the proper time as well as the failure of the lvnamic l he its lf, to operate to stop the car efore it can continue to move beyond h-se landings sutiiciently to reach and hit th overhead work placed above its up limit of travel or the bottom of the pit below its down limit of travel. The failure of the dynamic brake is determined in this case from the speed of the elevator car by means of a contact 86 operated by a centrifugal governor N driven by the movement of the car in the usual way. The contact 8G adapted to be closed when the elevator is running;' at fast speed and to open when the speed becomes a certain predetern'iincd amount lower than fa st speed.

The operation of the apparatus as shown in Figure 2 is as follows. Assume that the elevator car C is at its bottom terminal landinn l and that it is desired to operate it to cause it to travel to its top terminal floor landing I The lever 13 of the car switch (i will be moved to the right and its contact segment ll brought into contact with con-- i i t 15 of the switcu completing the ciruit f )r the up reversing switch coil as follows: from line I, by wire 16, contact 17 of the up reversing switch I. by wire 18, common wire 19 of contacts 20 and 21 of the switch (l. contact '20 segment. ll and contact 15, by wire 22. through a winding 23 of the up reversing; switch 1. hv wire 87. through contacts 29 of the up limit top switch 6, by wire 9-8. through contacts of the up limit stop .ich S Iby wire 82'}. junction point 90, by

The brake H will be released at the same The mam circui s to the motor are Q, R and S, and resistance T, the motor D shown in this figure being a direct current motor with separately excited field SF. Switch S is the accelerating switch to control the resistance T in series with the armature of the motor. Switch R may be called a fast speed switch in that it controls the accelerating switch S and is itself subject to the operating switch in the car. Switches 0, P and Q are adapted in case of the failure of the electric dynamic brake retardation or slow down of the car C in stopping at its terminal landings to operate to stop the car before it can continue to move beyond these landings sutticientl to reach and hit the overhead work placed above its up limit of travel or the bottom of the pit below its down limit of travel. The tr ilure ot the dynamic brake is determined in this case from the current in the motor armature, the voltage across the armature, and the current in the field. The contact on switch 0 is adapted to be closed if the voltage across the armatiu'e falls below a predetermined value: the contact on switch P is adapted to be closed it the c" at in the armature is above a predetei ed ralue: and the contact on switch Q is adapted to be closed it the current in the field is above a predetermined value.

The operation of the apparatus shown in Figure 3 is as follows: Assume that the car U is to be run from the bottom to the top terminal landings. The lever 13 of the car switch G will be moved to the right and its contact segment 14 brought into contact with contact 15 of the switch, establishing: an electrical circuit as follows: from the minus sup ply line, by wire 102. junction point 103, by wire 104, junction point 105, by wire 10G, contact 21, by wire 19. Contact 20, segment 14, contact 15, by wire 22, coil winding 01" re versing switch I. by wire 87, contacts 29 ot' limit switch (3, by wire 88, contacts of limit switch 5. by wire 89. junction point 90, by wire 111T, junction point 108, by wire it) to the plus supply line.

The winding 25 ot the reversing: switch 1 has been energized by the closing); of the circuit just trace-Ll and operates the reversing switch I to close ils contacts thereby closing circuits to the hoisting motor 1) as follows: from the plus sup ply line. by w re at contacts 51 and of switch. I, by wire 109, junction point 110. by wire 111, junction point 150, by wire 113. through armature 114 of motor D, by wire 115, junction point 151. by wire 118. contacts 37 and 17 of switch 1, by wires 119 and 1251, junction point 121.. resistance T, junction point 103, by wire 102. to the minus supply line. The closing of the reversing switch 1 completes the circuit for the brake magnet H, which operates and releases the mechanical brake. The circuit for the motor field is completed at the same time as follows: from the plus supply line, by wire 50, by

wire 122, contacts 123 and 124 on switch I now closed, by wire 12:, junction point 126, by wire 127, field SF of motor I), by wire 128, winding 129 of switch Q, by wire 130, junction point 131, by wire 132, junction point 105, by wire 104, junction point 103, by wire 1013 to the minus supply line. The hoisting motor will start as a result of the closing of the reversing switch, the motor field and brake magnet being energized, and hoist the car. Moving the operating switch lever 13 further to the right will bring its contact segment 14 in contact with another contact (32 in the switch. closing a circuit for the coil of switch It as follows: from the minus line to contact 20 of switch (1 as previously traced, segment 1:. contact (32. by wire 63, contacts (34 ot' llU.\!, switch 4, by wire 65. junction point tit). by wire (17, coil 133 of switch R. by wires 122 and 50 to the plus supply line. The coil of switch R has been energized and ti switch closes its contact 134, completing \illfa a circuit for the coil of the accelerating switch S as follows: armature 114 of motor 1). by wire 11:"). junction point 116, by wire 135, conta t 134. by wire 136, coil 18? of switch S, wire 138. junction point 110, by wire 111. junction point 150, by wire 113 to armature 114. Thus it is seen that the accelerating switch coil S is connected across the armature ot the motor. The coil ot switch S being energized will cause the resistance to be cut out in steps in the well known way.

The coil 139 of switch 0 is also connect v 1 across the armature of the motor between junction points 116 and 112, the remainder of the circuit being the same as traced above for the coil 1117 of switch S. The coil 139 is adapted to operate switch 0 to open its contact 140 when the voltage across the armature has attained a 'iredetermined value. which value in this case just slightly below line voltage. 'lheretore when the motor is running;- at i'ull speed, the contact of switch 0 will be open.

The coil 117 of switch l connected in series with the armature ot the motor and is adapted to operate and close the Contact .141 of this switch when the current in the armature of the motor has attained a predetermined amount, this amount being such that the motor will have suflicient dynamic braking action with this amount of current in the arnuiture. during the slowing down period.

The coil 129 of switch Q is connected in series with the tield winding of the motor as outlined above, and is adapted to operate and close the contact 142 of this switch when the current in the field circuit of the motor is sutticicnt to insure that the motor will have the proper dynamic braking action during the slowing; down period.

.Vith the car operating at full speed in the up direction. its approach to the top terminal floor landing will, as a first step in the operation of stopping at the top terminal tloor landing, effect the opening; of contacts (it of limit switch 4, thereby opening the circuit to the coil of switch R. Switch R will then open its contact 13% breaking the circuit to the coil 137 of switch S. Switch S will open its contacts and insert resistance T in series with the armature 11-l of the motor. Lwitch R also closes its; contact 152 completing: the dynamic brake circuit for the motor. This circuit includes coil 117 of switch P as above stated and may be traced from the motor armature 11%. by wire lib, coil 11'? of switl-h l, by wire 1523., contact 152 by wire lit through dyu mic brake resielancc i535" jun-wlion point 15th by wire 11?; t armature 114. It the proper dynamic slow down is r'ili -taimd the voltage across the arn'iature oi the motor will be reduced sui'liciently to cause coil 1319 on switch to be (lo-energized enough so that contact 140 on this switch will close: the current in the dynamic brake circuit will remain high enough to keep coil 117 of switch P energized and contact 14-1 of this switch closed; also, the current in the iicld will re main high enough to keep coil i239 ot sw tch Q energized and Contact 142 of this switch closed. As the car moves up and. the cam 10 will strike the roller on limit switch and open contacts shortly after switch was operated. Vith normal conditions. that is with the proper dynamic braking: action present, the opening: of contacts will have no further cttect a circuit to the reversing switch coil 23, will still be complete as fo lows: from the minus supply line through contacts 29 of limit switch 6 as previously traced, by wire 100, contact 142 ot switch Q now closed, by wire 1.43, contact 1%?1 of switch P now closed, by wire 14-4. contact 1 0 oi switch 0 now closed, by wire 101. contact W of limit switch (4; this contact having: closed when car moved away from lower terminal landing. bv wire 14:) junction point 96L by Wire junction point 108. by wire .3!) to the plus supply line. lVhen the cam 10 on car strikes limit switch (3. contacts 2% on this switch will be opened. breaking the circuit oi the reversing switch coil 23 just traced, there by causing the reversing switch to open and cut off current from the motor and apply the brake H and stop the car at the top terminal floor landing.

In this case as in connection with Figures 1 and 2, it is seen that in the operation outlined. the dynamic brake action of the motor will have reduced the speed of the car sufficiently before the application of the mechanical. brake H to insure that the car will stop at the top terminal floor landing and will not slide beyond this landing enough to strike the overhead work.

Should the dynamic brake action obtained ou icd to giv the proper dynamic braking of switch P vill be, stil ed to cause t switch to rl the current in the t to e the proper brrhe action, the coil 129 M l-rwitrh will he sulli 'icntly uc-cncr to cause switch to oprn its (1:12.11 it any or mien of [hose couditio the car :rt practicallv lull sprcd and he coil a 9 opening oi contacts ot limit switch 5 will break he Ctltlllt1 01illONYUl'Siilg switch thereby causing his switch to open 7 s and cut of? current from the mo :pl v the mechanical brake H when a point in its travel cl'urespondth point ol opening of limit switcu 5. ii r-nee through which the car c More strikiiig' the overhead pere the car to be broiled to rest by the me .anical brake alone with little chance of the Ling far enough to strike the overhead ll hcn the cam 1001a the car leaves the limit str p switches 7. 8 and 9, they are closed, each leing returned to its closed position, as by a spring 81. The closing of switches T, 8 and 9 conditions circuits to be closed by movcment to the left ot the operating swi'i ch lever 13 of the operating switch (l tor a down direction of car travel. Since the #ircuits throu 'h the limit stop sw ches '7, cl and S) are closed similarly to the ci crnits clo ed thr '=i the up limit slop Witches l 5 and (i dlwcrilrrl herein, it is not thought necessary to trace them or describe the, down operation ot' the car with my invr di-zm applied thereto.

What 1 claim 0:: new and desire to srcure by Letters Patent of the United States is:

l. l control system tor un cleator car (":')i:l} i'i:si3l 1;',;i motor for raising and lowering the car, a source of power tor said motor, a dynamic brake circuit to? said motor, s itching; mechanism for disconnecting said motor from said source, a switch automatically operated upon the car reaching a predetermined point in the hatchway to complete said dynamic brake circuit, a second switch automatically o iierated upon the car pa sing: a predetermined distance beyond said point to cause the disconnection of said motor from said source, and a third switch automatically operated upon the car passing ba vond said point, but prior to the operation of said second switch, to cause the disconnection of said motor from said source in the event of insufiicient dynamic braking ac- 1 disconnect said inotor from said source, and

a third switch automatically operated after the car has passed said point but before it has passed said certain distance beyond said point to cause the operation of said switching mechanism to disconnect the motor from said source in the event that the action of the slow-down mechanism, when operated, is insuflicient to cause the desired slowing down of the motor.

3. A control system for an elevator car comprising, a motor for raising and lowering the car, a source of power for the motor, a dynamic brake circuit for the motor, a switch operable as the car approaches a predetermined point to complete said circuit, a second switch operable as the car approaches still closer to said point to cause the disconnection of the motor from said source, and a third switch dependent on the current in the dynamic brake circuit for rendering the operation of the second switch ineffective.

4. A control system for an elevator car comprising, a motor for raising and lowering the car, a source of power for the motor, a dynamic brake circuit for the motor, a switch operable as the car approaches a predetermined point to complete said circuit, a second switch operable as the car approaches still closer to said point to cause the disconnection of the motor from said source, and a third switch, having an operating winding in the dynamic brake circuit, for by-passing the second named switch.

5. In combination, an alternating current multiphase motor, a source of power for said motor, means for dynamically braking said motor, means for later causing the disconnection of said-motor from said source, a switch having windings controlled by the motor current during the operation of the dynamic braking means for rendering the second named means ineffective.

' 6. In combination, an alternating current motor having slow and fast speed windings, a source of power for said motor, means operable while the motor is running for connecting the slow speed windings of said motor to the source so as to dynamically brake the motor, means for disconnecting the motor from said source, and means dependent on the current in the slow speed windings of the motor during the dynamic braking operation for controlling the operation of the disconnecting means.

7. In combination, an alternating current motor having slow and fast speed windings, a source of power for said motor, means operable while the motor is running for connecting the slow speed windings or" said motor to the source so as to dynamically brake the motor, means for disconnecting the motor from said source, and a switch having windings in circuit with the slow speed windings of the motor for'controlling the operation of said disconnecting means.

In testimony whereof, I have signed my name to this specification.

DAVID L. Linnouis'r. 

